Pallets of varying configurations and in varying materials have long been used in the loading of goods for forwarding by various types of transport. The most common material is and has been wood, a robust material of which a pallet can be produced relatively easily. Wooden pallets are however comparatively heavy, which limits the useful load e.g. for a lorry. Wooden pallets have other disadvantages as well. They have a tendency to absorb moisture, which makes them even heavier as well as discouraging the loading of moisture-sensitive goods such as flour. They are also difficult to clean due to pores and cavities in the wood. They can also contain insects and other creeping creatures, which altogether make them unsuitable from a hygienic point of view. Regarding these considerations as well as environmental considerations, other materials have been brought forth such as paper and cardboard, which are wound into tubing with a number of layers that are joined together with suitable adhesive. In this way a significantly lighter and less expensive construction of the pallet is obtained, with added advantages such as the use of waste material, better hygiene and a pallet that is 100% recyclable.
The problem up to now has been that no one has proposed an optimal construction for strength, stiffness and simplicity in the production of tubes in a pallet made of paper or cardboard. SE-B-459 251 for instance describes a pallet made of a number of base parts in the form of square tubes made of several layers of paper or cardboard. The description gives no information regarding how the layers are joined to each other or how the pallet is treated to withstand moisture. CH-486 376 describes a pallet with three longitudinal base units and a loading deck on these. All components consist of paper wound in several layers, however with a circular form which significantly decreases the possibility of joining these with each other, and which has a detrimental effect on the strength and stiffness of the pallet. Neither does this document deal with the joining of the layers in the tubes.
As to the joining of layers and the moisture resistance of the final product, it is generally so that before winding, the cardboard layers must be treated with suitable media so that they will stick to each other and give the desired strength and in certain cases moisture-protection so that the board does not become damp.